Surgical Technique

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Introduction

The LEGION™ Revision Knee System has been designed to offerthe orthopaedic surgeon improved options to deal with thecomplexities associated with revision knee arthroplasty, whileproviding them in a manner that is relatively simple to execute.The instrumentation has been developed to be an easy-to-usesystem that will allow the surgeon to obtain accurate andreproducible results while improving the ease with which asurgeon can manage bone mass, restore limb alignment andimprove knee function. Failed total knee arthroplasty due toaseptic loosening, osteolysis, instability, malalignment or infectioncan be reconstructed using the LEGION Revision Knee System.

Key elements in revision knee arthroplasty include therestoration of proper limb alignment, achievement of properprosthetic component position, restoration of knee biomechanicsand balanced medial/lateral and flexion/extension gaps. The achievement of these goals will lead to proper patellofemoral mechanics, functional range of motion and optimized patient satisfaction.

David J. Jacofsky, MD

Contributing CliniciansDennis Brown, MDMontgomery Orthopedic SurgeonsDayton, OH

George Haidukewych, MDFlorida Orthopedic InstituteTampa, FL

David Jacofsky, MDThe CORE InstituteSun City, AZ

Anthony McPherron, DOSpecialty Orthopaedics, Inc.Plymouth, IN

Matthew Nadaud, MDKnoxville Orthopedic ClinicKnoxville, TN

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Tibial Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Non Offset Tibial Sizing and Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Offset Tibial Sizing and Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Femoral Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Non Offset Femoral Sizing and Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Offset Femoral Sizing and Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Femoral Sizing and Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Trialing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Resurfacing Patellar Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Biconvex Patellar Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Implant Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Implantation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Nota Bene:The technique description herein is made available to the healthcare professional to illustrate the authors’ suggested treatment for the uncomplicated procedure. In the final analysis, the preferred treatment is that which addresses the needs of the patient.

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Preoperative Evaluation

The preoperative evaluation of a failed total knee arthroplasty begins with acomplete history and physical examination. Determination of the etiology orfailure will also require radiographic evaluation, occasionally the use oftechnetium bone scans, the use of laboratory studies and/or aspiration torule out the possibility of indolent infection. It is imperative that the cause offailure be determined preoperatively in order to help maximize thelikelihood of postoperative success.

If bone defects secondary to osteolysis exist preoperatively then thesurgeon performing the procedure must understand the implications of thisbone loss as well as techniques required to manage them.

Exposure

Exposure of the revision total knee can be complicated by previousincisions, stiffness or a fibrotic soft tissue envelope. In general, greaterexposure is required for a revision total knee arthroplasty as comparedwith that of a primary procedure. Proper tissue planes medially andlaterally must be elevated and fasciocutaneous flaps must be maintainedin order to minimize wound healing complications. In general, a standardmedial parapatellar arthrotomy is used when feasible. An extensileexposure proximally such as a quadriceps snip, or distally such as a tibialtubercle osteotomy, may be required to achieve adequate exposure.

Component Removal

After adequate exposure of all components has been achieved, attentionis turned to component removal. This is typically achieved throughdissection of the interface between the prosthesis and the cement or atthe prosthetic/bone interface. Many surgeons prefer to remove thefemoral component first in order to improve visualization of the posteriortibial component. A thin, flexible osteotome or a thin oscillating saw maybe used to disrupt the prosthetic interface in order to allow removal withminimal bone loss. Alternative techniques include the use of a Midas-Rex burr or a Gigli saw to free this interface. Angled osteotomes may behelpful in freeing the condylar portions of the femoral components. If theinterfaces have been adequately freed, minimal force is typically required toremove the femoral component. Excessive force to remove the componentmay lead to femoral fracture. Removal of the tibial component is thencarried out in a similar manner. Occasionally, exposure of the lateral side

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may be more difficult, and the use of a small capsular incision about the lateral aspect of the joint may be required to gain access to theposterolateral aspect of the tibial component. If disruption of theinterface at the level of the plateau does not allow for easy implantremoval, a cortical window may be made in the metadiaphysis of thetibia to allow a bone tamp access to the keel of the prosthesis. As bonecement fails most easily in tension, a controlled, well-placed blow willoften dislodge the tibial component. If the patellar button is securelyfixed, well-positioned and does not show excessive wear then it may beleft and protected for the remainder of the case. If the patellar buttonmust be revised, removal is most easily performed with a sagittal saw atthe cement interface. Remaining cement and polyethylene plugs fromthe component may then be removed with a small, high-speed burr.Great care must be taken during this stage of the procedure in order toensure adequate patellar bone stock remains for revision componentplacement so that fracture is prevented. Once components have beenremoved, the remaining cement can then be removed with curettes,rongeurs or cement osteotomes. The wounds can be irrigated with awater pick to remove loose debris and attention can then be turned tothe reconstructive portion of the procedure.

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Ream

1.Drill a pilot hole with the 9.5mm intramedullarydrill, if necessary.

2.Ream the canal until cortical contact is achieved using progressively larger diameter reamers(Figure 1).

3.Choose between the two methods of instrument stabilization:

A.Last Reamer: Leave the last reamer in the tibial canal.

B. Trial Stem Connection Rod Assembly:

– Remove the last reamer, making note of the depth and diameter (Figure 2).

– Attach the Trial Stem Connection Rod to theappropriate diameter trial stem and insertthe Trial Stem Connection Rod Assembly into the tibial canal.

Tip: Long stems are offered in 120, 160, 220mmStraight; 220 and 280mm Bowed. Markings of depth length are laser marked on the reamers.

Tip: The cutting flutes on the press-fit stems are1mm larger in diameter than the reamers.

Tibial Preparation

Figure 2

Figure 1

7Figure 4 Figure 5

a

c

d

b

f

e

Tibial IM Alignment Guide

Tibial IM Instrument Assembly:Ensure the horizontal alignment bar knob (Figure 3b) is in the locked position. Slide the cutting block onto the vertical alignment bar (Figure 3c), position at the 0mm mark and tighten the tibial cutting block thumbscrew (Figure 3d).

1.Attach the 1mm Stylus to the slot capture of theTibial Cutting Block by inserting the stylus footinto the cutting slot.

2.Slide the Tibial IM Assembly onto the Reamer (or Trial Stem Connection Rod Assembly) (Figure 4).

3.Adjust the vertical alignment bar towards theanterior tibia and lock in position (Figure 5c).Lower the IM assembly so that the 1mm stylustouches the least affected side of the tibialplateau (Figure 5e) and tighten the IM collet inposition (Figure 5f).

4.With the IM guide secured to the reamer shaft(or connection rod) by the tightened collet, thetibial cutting block can be rotated around theanterior tibia for optimum access by looseningthe thumbscrew (Figure 5b).

Figure 3

c

b

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Tibial Resection

Note: Ensure that the IM assembly is in thelocked position by inserting a 3.5mm hexscrewdriver into the female end of thethumbscrews (Figure 6a, b, d), turningclockwise until tight.

1.Pin the tibial cutting block to the tibia by insertingpins first through the central holes in the 0mmposition, then the oblique hole (Figure 6).

Tip: Using headless pins through the centralholes marked 0mm will allow the block to beshifted to +2, +5 or +7mm should additionalresection be needed.

2.Remove the stylus.

3.Using a PROFIX™ sawblade, resect the proximaltibia (Figure 7).

Tip: The LEGION™ revision tibial tray has a 0°posterior slope. Rotational alignment is not a factor.

4. Remove the pins and loosen the IM collet.Remove the IM assembly, leaving the reamer in the tibial canal.

Tibial Preparation

Figure 6

Figure 7

a

b

pinsd

c

Sizing and Placement

1.Assess the A-P and M-L size of the resected proximal tibia with the Tibial Drill Guides and select the proper size.

Tibial Drill Guide/Neutral Bushing Instrument Assembly:Insert the Tibial Neutral Bushing into the appropriate sized Tibial Drill Guide. Push in until fully seated.

2.Place the Tibial Drill Guide/Neutral Bushing Assembly over the reamer (or TrialStem Connection Rod Assembly) and assessthe A-P and M-L position and rotation toensure adequate tibial coverage. (If adequatecoverage is not achieved, proceed to OffsetTibial Sizing and Placement, page 11).

3.Using headless pins, pin the Tibial Drill Guide tothe proximal tibia (Figure 8).

Preparation of the Female Taper Counterbore

4.Remove the Neutral Bushing and reamer (or TrialStem Connection Rod Assembly).

Tip: If needed, the Revision T-Handle can be usedto remove fixed reamers or in case the trial stembecomes well-fixed within the canal, the universalextractor can be attached to the end of the trialstem connection rod to aid in removal.

5.Insert the Tibial Counterbore Guide Bushing intothe Tibial Drill Guide (Figure 9).

Non Offset Tibial Sizing and Placement

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Figure 9

Figure 8

10

Figure 10

Figure 11

Figure 13Figure 12

Counterbore Reamer Instrument Assembly:Depress the button on the Counterbore Depth Stop and slide the depth stop over the reamer with the “IM CANAL” marking towards the cutting end of the reamer. Then attach to the power drill. Position the depth guide to the “TIBIA” marking (Figure 10).

6.Insert the Counterbore Reamer Assembly into theguide bushing and ream until the depth stopmakes contact with the guide bushing (Figure 11).

7. Remove pins and drill guide.

Tibial Trial Preparation

Tibial Trial/Trial Stem Instrument Assembly:Align the laser mark on the J-hook of the trial stem to the laser mark on the posterior side of the distal face of the female tibial trial taper (Figure 12). Push in the trial stem and make a quarter-turn to engage the J-hooks.

8.Insert the Tibial Trial/Trial Stem Assembly into the tibial canal (Figure 13).

Sizing and Placement

1. If adequate tibial coverage is not achieved withthe Neutral Tibial Bushing Assembly (Figure 14),remove the assembly from the tibial plateau.

Tibial Offset Bushing Instrument Assembly:Insert the 2, 4 or 6mm offset tibial bushing into the appropriate sized tibial drill guide. In this surgical technique a 4mm offset is used.

2.Replace the Tibial Offset Bushing Assembly overthe reamer (Figure 15).

3.Rotate the tibial offset bushing about the tibia untilproper tibial coverage is achieved (Figure 16).

4.Using headless pins, pin the tibial drill guide tothe proximal tibia (Figure 17).

5.Make note of the location of the arrow markingon the offset bushing to the number on thetibial drill guide (Figure 17a). This numberreferences the position (location) of the offsetcoupler trial/implant when connected to the trialstem/implant.

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Offset Tibial Sizing and Placement

Figure 15

Figure 14

Figure 16

a

Figure 17

Figure 20 Figure 21

Figure 22

Offset Tibial Sizing and Placement

Figure 18

Preparation of the Female Taper Counterbore

6.Leaving the pins in place, remove the offsetbushing assembly from the tibial plateau, thenremove the reamer (or trial stem connectionrod assembly).

Tibial Counterbore Guide Bushing Assembly:Insert the tibial counterbore guide bushing into the appropriate sized tibial drill guide.

7. Replace the tibial counterbore guide bushingassembly over the pins (Figure 18).

Counterbore Reamer Instrument Assembly:Depress the button on the Counterbore Depth Stop and slide the depth stop over the reamer with the “IM CANAL” marking towards the cutting end of the reamer. Then attach to the power drill. Position the depth guide to the “TIBIA” marking (Figure 19).

8.Insert the Counterbore Reamer Assembly into theguide bushing and ream until the depth stopmakes contact with the guide bushing (Figure 20).Remove the Counterbore Reamer Assembly.

9. Remove the Tibial Counterbore Guide BushingAssembly and pins from the tibial plateau.

Preparation of the Offset Coupler Counterbore

Trial Stem Guide Assembly:Attach the 120mm length trial stem, using the diameter ofthe last reamer used, to the Trial Stem Connection Rod.

10.Place the Trial Stem Guide Assembly into thetibial canal (Figure 21).

11.Place the Counterbore Reamer Assembly, stillpositioned at the “TIBIA” marking, over the TrialStem Guide Assembly and ream until the depthstop contacts the tibial plateau (Figure 22).

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Figure 19

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Tibial Trial Preparation

Note: Ensure the offset coupler trial is in thelocked position. If not, insert a 3.5mm hexscrewdriver in the male end of the coupler turningclockwise until tight.

Tibial Trial/Coupler/Stem Instrument Assembly: Align the laser mark on the male end of the offset coupler J-hook with the line mark on the posterior side of the distal face of the female tibial trial taper. Push in the offset coupler trial and turn coupler a quarter-turn to engage J-hook. Align the male end of the trial stem J-hook to the female end of the offset coupler. Push in the trial stem and make a quarter-turn to engage the J-hook (Figure 23).

1. Insert the 3.5mm hex screwdriver into the proximal end of the tibial trial until thescrewdriver is engaged with the hex connection of the coupler trial (Figure 24). Unlock the coupler trial by turning the hex screwdrivercounterclockwise.

2.Adjust the coupler to the predetermined position(obtained previously in the Sizing andPlacement section, page 11) by aligning thecorrect clock position on the offset coupler trialto the line marking on the tibial trial (Figure 25).(In this case, a 7 o’clock position was used.)

3.Once positioned, turn the hex screwdriverclockwise to lock the predetermined offset into position.

4.Insert the tibial trial/offset coupler trial/stem trialassembly into the tibial canal (Figure 26).

5.Assess the preliminary A-P and M-L position ofthe tibial trial tray. Final rotation of the tibial trialtray will be determined from the femoral trial andconstrained tibial trial insert.

Figure 23

Figure 25

Figure 24

Figure 26

Figure 28

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Ream

1.Drill a pilot hole with the 9.5mm intramedullarydrill, if necessary.

2.Ream the canal until cortical contact is achievedusing progressively larger diameter reamers(Figure 27).

3.Choose between the two methods ofinstrument stabilization:

A. Last Reamer: Leave the last reamer used in the femoral canal.

B. Trial Stem Connection Rod Assembly:

– Remove the last reamer, making note of the depth and diameter (Figure 28).

– Attach the Trial Stem Connection Rod to the appropriate diameter trial stem and insert the Trial Stem Connection Rod Assembly into the femoral canal.

Tip: Long stems are offered in 120, 160, and 220mmStraight; and 220 and 280mm Bowed. Markings ofdepth lengths are laser marked on the reamers.

Tip: The cutting flutes on the press-fit stems are1mm larger in diameter than the reamers.

Femoral Preparation

Figure 27

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Assess Femoral A-P Size and Stem Offset Position

1.Slide the Offset Indicator (pointing medially) over the last reamer or trial stem connection rodassembly (Figure 29).

2.Position the A-P sizing plate relative to theanterior cortex of the femur and adjacent to theoffset indicator (Figure 30).

3.Assess proper A-P size.

Tip: In addition to the indicator marks fordetermining the preliminary offset needed, the A-P Sizing Plate has indicator marks locatedon the sides of the plate to assess distal andposterior wedge resections.

4.Once the A-P size is determined, assess A-Pposition relative to the reamer position usingthe Offset Indicator. Rotate Offset Indicatorparallel to the epicondylar axis and make noteof the Offset Indicator stylus position relative tothe offset markings on the medial face of theA-P sizing plate.

5.Remove Offset Indicator and A-P sizing plate.

Figure 30

Figure 29

Option: Epicondylar Axis Target – AnatomicAssessment of Offset Using Epicondyles

1.Place Offset Indicator (pointing medially) on thereamer (Figure 31).

2.Position the A-P sizing plate relative to theanterior cortex of the femur and adjacent to theoffset indicator.

3.Align the center of the epicondyles along theline markings of the Epicondylar Axis Target(Figure 32). It is not necessary to have the centerof the epicondyles within the open space of thetarget axis. Vary the A-P sizing plates anddistal augment estimates until epicondylesalign with the Epicondylar Axis Target. The goalis to restore the desired joint line positioning.

4.Once a desired position of the A-P sizingplate, relative to the femoral epicondyles, isachieved, the distal and posterior wedgeassessments can be made by referencing thewedge resection level marks on the A-PFemoral Sizing Plate.

5.Retain position of the A-P sizing plate and makenote of the offset indicator position (Figure 33),relative to the indicator marking on the medialface of the A-P sizing plate. This will give arough estimate of offset needed.

Femoral Preparation

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Figure 31

Figure 33

Figure 32

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Option: M-L Femoral Sizing with Valgus Guide Sizing Plate

Valgus Guide Instrument Assembly: Attach the size 3-8 neutral 6º valgus collet to the valgus alignment guide and ensure that the “LATERAL” notation on the collet is correctly positioned for a left or right knee. Slide the distal cutting block on the post of the valgus guide (Figure 34).

1.Attach the Valgus Guide Sizing Plate to theValgus Guide Assembly by sliding over the distalsurface of the valgus guide (Figure 35).

2.Assess the M-L femoral size with the size-correlating steps of the Valgus Guide SizingPlate in relation to the femur (Figure 35a).

Figure 34

Figure 35

a

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Femoral Preparation

Distal Femoral Resection(s)

Valgus Guide Instrument Assembly: Attach the size 3-8 neutral 6º valgus collet to the valgus alignment guide and ensure that the “LATERAL” notation on the collet is correctly positioned for a left or right knee. Slide the distal cutting block on the post of the valgus guide (Figure 36).

1.Slide the valgus guide assembly over the shaftof the reamer (or Trial Stem Connection RodAssembly) and flush with the distal femur(Figure 37).

2.Tighten the valgus collet to the reamer (Figure 37a).

Tip: The distal cutting block is designed for a 1.5mm “clean-up” cut, 5, 10 or 15mmwedge cut.

Option: Attach the 1mm stylus to the distalcutting block by inserting the stylus foot intothe distal slot and position the stylus tip onthe least affected side (Figure 38).

3.Pin the distal cutting block, using at least oneoblique pin, and resect the distal femur (Figure 39).

Distal Femoral Wedge Resection(s):

1. If needed, resect the appropriate distal femoralwedges through the distal cutting block (Figure 40).

2.Remove the pins, loosen the valgus guidecollet, and remove the guide assembly from the reamer.

Figure 37

Figure 36

Figure 39

Figure 38

a

Figure 40

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A-P Femoral Resections/Posterior Wedge Resection(s)

1.Attach the appropriate A-P Hemi Distal Shims,matching the size of the distal wedgeresections, to the posterior aspect of the A-PCutting Block (Figure 41).

Neutral Femoral Resection Instrument Assembly:Attach the neutral 6º valgus collet to the selected A-P femoral cutting block ensuring that the “LATERAL” notation on the collet is correctly positioned for a left or right knee (Figure 42).

2.Slide the Neutral Femoral Resection Assemblyover the shaft of the Reamer (or Trial StemConnection Rod Assembly) until flush withthe distal femur (Figure 43).

Note: Quick-connect handles may be used toassist in setting rotation.

3.Assess the A-P and M-L position ensuringrotation of the A-P cutting block is aligned withthe epicondylar axis. (If appropriate position isnot achieved, proceed to Offset Femoral Sizingand Placement, page 22.)

Non Offset Femoral Sizing and Placement

Figure 43

Figure 42

Figure 41

Non Offset Femoral Sizing and Placement

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Note: Quick-connect handles may be left in the A-P cutting block while resections are made. Thispage shows the handles removed for visual clarity.

4.Tighten the neutral 6º valgus collet to the reamershaft (or Trial Stem Connection Rod Assembly).Pin the A-P cutting block to the distal femurthrough the central hole and secure with obliquepin(s) through the side of the A-P cutting blockand distal shims (Figure 44).

Note: To secure distal shims, oblique pins mustbe used (Figure 44a).

5.Resect the anterior femur above the anteriorsurface of the A-P cutting block (Figure 45).

6.Resect the posterior condyles under the posteriorsurface of the A-P cutting block (Figure 46).

7. If wedges are needed to fill bony defects, twomore slots are available for 5 or 10mm posteriorwedge cuts (Figure 47).

8.Resect the posterior chamfer (Figure 48).

Note: Posterior chamfer cuts are not needed if distal or posterior wedge cuts are made.

9.Resect the anterior chamfer (Figure 49).

Figure 44

Figure 45

Figure 46

Figure 47

Figure 48

Figure 49

a

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Non Offset Femoral Sizing and Placement

Figure 50

Figure 51

Figure 52

Figure 53

Preparation of the Female Taper Counterbore

1.With the A-P cutting block pinned in place,remove the Neutral 6º Valgus Collet and Reamer(or Trial Stem Connection Rod Assembly).

Tip: If needed, the Revision T-Handle can be usedto remove fixed reamers or in case the trial stembecomes well-fixed within the canal, the universalextractor can be attached to the end of the trialstem connection rod to aid in removal.

2.Insert the femoral counterbore guide bushinginto the A-P femoral cutting block, ensuringthat the “LATERAL” notation on the bushing iscorrectly positioned for a left or right knee(Figure 50).

Counterbore Reamer Instrument Assembly:Depress the button on the Counterbore Depth Stop and slide the depth stop over the reamer with the “IM CANAL” marking towards the cutting end of the reamer. Then attach to the power drill. Position the depth guide to the “FEMUR” marking (Figure 51).

3.Insert the counterbore reamer assembly into theguide bushing and ream until the depth stopcontacts with the guide bushing (Figure 52).

4.Remove the pins and A-P cutting block from thedistal femur.

Femoral Trial Preparation

Femoral Trial/Trial Stem Instrument Assembly:Align the laser mark on the J-hook of the trial stem to the laser mark on the side of the femoral trial taper. Push in the trial stem and make a quarter-turn to engage the J-hooks.

5.Using a 3.5mm hex screwdriver, screw on theappropriate distal, posterior or L-wedge trial(s) to the femoral trial (Figure 53).

Tip: The posterior wedge trials screw in from a 10º angle.

6.Insert the Femoral Trial/Trial Stem assembly intothe femoral canal. Proceed to page 27, FemoralHousing Box Resection.

Offset Femoral Sizing and Placement

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1 o’clock

7 o’clock

Figure 54

Figure 55

Figure 58

Figure 57

11 o’clock

6

39

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Figure 56

A-P Femoral Resections/Posterior Wedge Resection(s)

1. If appropriate femoral position is not achievedwith the Neutral 6º Valgus Collet, remove theNeutral 6º Valgus Collet and A-P cutting blockfrom the distal femur.

2.Ensure that the A-P Hemi Distal Shims, matchingthe size of the distal wedge resections, areattached to the posterior aspect of the A-Pcutting block.

Offset Femoral Collet Instrument Assembly: Insert the 2, 4 or 6mm offset femoral collet to the appropriate sized A-P cutting block, ensuring that the “LATERAL” notation on the collet is correctly positioned for a left or right knee (Figure 54). In this surgical technique a 4mm offset is used.

3.Slide the offset femoral collet assembly over thereamer (Figure 55).

4.Rotate the arm of the offset collet until the A-P cutting block is positioned appropriately. The clock position of the arm references thepositioning of the femoral collet relative to thecanal (Figures 56-58). (In this surgical techniquea 7 o’clock position is referenced.)

5.Assess the A-P and M-L position ensuring therotation of the A-P cutting block is aligned withthe epicondylar axis.

Note: Quick-connect handles may be used toassist in setting rotation.

Note: Quick-connect handles may be left in the A-P cutting block while resections are made. Thispage shows the handles removed for visual clarity.

6.Tighten the offset valgus collet to the reamershaft (or Trial Stem Connection Rod Assembly).Pin the A-P cutting block to the distal femurthrough the central hole and secure withoblique pin(s) through the sides of the A-Pcutting block and distal shims (Figure 59).

Note: To secure distal shims in place, oblique pins should be used (Figure 59a).

7. Resect the anterior femur above the anteriorsurface of the A-P cutting block (Figure 60).

8.Resect the posterior condyles under theposterior surface of the A-P cutting block (Figure 61).

9. If wedges are needed to fill bony defects, twomore slots are available for 5 or 10mm posteriorwedge cuts (Figure 62).

10.Resect the posterior chamfer (Figure 63).

Note: Posterior chamfer cuts are not needed if distal or posterior wedge cuts are made.

11.Resect the anterior chamfer (Figure 64).

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Figure 61

Figure 62

Figure 64

Figure 63

Figure 60

Figure 59 a

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Offset Femoral Sizing and Placement

Figure 65

Figure 67

Figure 66

Preparation of the Female Taper Counterbore

12.Remove the offset bushing and reamer, leavingthe pinned A-P block on the distal femur.

Note: If using a 4mm offset (16mm or largerdiameter reamer) or 6mm offset, the obliquepins and A-P cutting block will need to beremoved so that the reamer can be extractedfrom the femoral canal.

13.Insert the femoral counterbore guide bushinginto the A-P cutting block, ensuring that the“LATERAL” notation on the collet is correctlypositioned for a left or right knee (Figure 65).

Counterbore Reamer Instrument Assembly:Depress the button on the Counterbore Depth Stop and slide the depth stop over the reamer with the “IM CANAL” marking towards the cutting end of the reamer. Then attach to the power drill. Position the depth guide to the “FEMUR” marking (Figure 66).

14.Insert the Counterbore Reamer Assembly into the guide bushing and ream until the depth stopmakes contact with the guide bushing (Figure 67).

15.Remove the pins, Femoral Counterbore GuideBushing and A-P Cutting Block from the distalfemur.

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Preparation of the Offset Coupler Taper Counterbore

Trial Stem Guide Assembly:Attach the 120mm length trial stem, using the diameter of the last reamer used, to the Trial Stem Connection Rod.

16.Place the Trial Stem Guide Assembly into thefemoral canal (Figure 68).

17. Insert the Counterbore Reamer Assembly, stillpositioned at the “FEMUR” mark, over the trialstem guide and ream until the depth stopcontacts the distal femur (Figure 69).

18.Remove the counterbore reamer assembly andtrial stem guide assembly.

Figure 69

Figure 68

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Femoral Trial Preparation

Note: Ensure the offset coupler is in the lockedposition by inserting a 3.5mm hex screwdriver inthe male end of the coupler, turning clockwiseuntil tight.

Femoral Trial/Coupler Trial/Stem Trial Assembly:Align the laser mark on the male end of the offset coupler J-hook with the laser mark on the taper of the femoral trial. Push in the offset coupler trial and turn the coupler a quarter-turn to engage J-hook. Align the male end of the trial stem J-hook to the female end of the offset coupler. Push in the trial stem and make a quarter-turn to engage the J-hook (Figure 70).

1. Insert the 3.5mm hex screwdriver into the distalend of the femoral trial until the screwdriver isengaged with the hex connection of the couplertrial (Figure 71). Unlock the coupler trial byturning the hex screwdriver counterclockwise.

2.Adjust the coupler to the predetermined position (obtained previously in the OffsetSizing and Placement section, page 22), byaligning the correct clock position on the offsetcoupler trial to the line marking on the femoraltrial (Figure 72). (In this surgical technique, a 7 o’clock position was used.)

3.Once positioned, turn the hex screwdriverclockwise to lock the predetermined offset into position.

4.Using a 3.5mm hex screwdriver, screw on theappropriate distal, posterior or L-wedge trial(s) to the femoral trial (Figure 73).

Tip: The posterior wedge trials screw in from a 10º angle.

5.Insert the Femoral Trial/Offset Coupler Trial/StemTrial/Augment Trial assembly into the femoralcanal (Figure 74).

Offset Femoral Sizing and Placement

Figure 73

Figure 70

Figure 72

Figure 74

Figure 71

Femoral Sizing and Placement

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Femoral Housing Box Resection

1.Pin the femoral trial through the anterior flange(Figure 75).

2.Choose the Housing Resection Collet matchingthe femoral trial size (either 1-2 or 3-8). Attachthe collet to the femoral trial by pulling forwardon the tabs of the collet (Figure 76) and slidingthe housing collet (anterior to posterior) into theslots on the distal face of the femoral trial. Thehousing collet should move freely in theanterior/posterior positions.

3.Attach the housing reamer dome and the P-Sreamer sleeve to the patellar reamer shaft.Ream through the housing resection collet inboth the anterior and posterior positions untilthe depth stop contacts the collet (Figure 77).

4. Impact the housing box chisel through thehousing resection collet to square the corners ofthe housing. The housing box chisel should beused anteriorly and posteriorly to ensure that thefull length of the box is prepared (Figure 78). Figure 76

Figure 77

Figure 78

Figure 75

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Femoral Trial Cam Module Assembly

1.Select the appropriate sized Femoral Trial CamModule (matching the femoral trial size selected).

2.Insert the arms of the femoral cam module intothe anterior aspect of the femoral trial box androtate downward until seated (Figures 79 & 80).

Femoral Sizing and Placement

Figure 79

Figure 80

Trial Range of Motion and Tibial Rotational Assessment

1.With the tibial trial/trial stem in the tibia andthe femoral trial/trial stem in the femur, insertthe constrained articular insert trial into thetibial trial tray.

2.Perform a trial range of motion (Figure 81). Thetibial trial should be rotationally symmetric withthe femoral trial in full extension with theextensor mechanism reduced.

3.Mark the rotation on the tibia utilizing the twoanterior marks on the tibial trial tray (Figure 82).Remove the articular insert trial.

4.Using a short-headed spike through the tibialtrial, pin the trial tray into the proximal tibia tolock the rotational orientation of the tibial trial.

29

Trialing

Figure 81

Figure 82

Trialing

30

Tibial Wedge Resection(s)

1.Select the appropriate wedge resection guide(Figure 83a, b, c) and orient to the correct M-Ldirection.

2.Insert the locking quick-connect handle throughthe wedge resection guide by depressing the ball tip of the handle and inserting the handlethrough the guide into the anterior quick-connectpocket of the tibial trial tray (Figure 84a). Lockthe wedge resection guide by tightening theknob on the quick-connect handle (Figure 84b).Then tighten the thumbscrew on the wedgeresection guide (Figure 84c).

3.Using headless pins, pin the wedge resectionblock to the anterior tibia in the most distal holes.

Note: Insert an additional pin at the level of tibial wedge resection (5, 10 or 15mm). This willbe used as a guide for the sagittal clean-up cutfor hemi-stepped wedges (Figure 85).

Figure 83a

Figure 83b Figure 83c

7º Full Tibial Wedge

Hemi-Stepped Tibial Wedge Hemi-Angled Tibial Wedge

Figure 84

ab

c

Figure 85

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Figure 86

4.Resect for tibial wedges (Figure 86).

5.Loosen the quick-connect knob to release thehandle and attached the resection guide fromthe tibial tray.

6.Remove the tibial trial assembly from the canal.

Note: For hemi-stepped wedges, make asagittal clean-up cut by using the pin locatedat the resection level as a guide (Figure 87).

Figure 87

32

Tibial Wedge Assembly and Fin Punch

1.Using a 3.5mm hex screwdriver, screw on theappropriate tibial wedge(s) into the distal aspectof the tibial trial tray (Figure 88) and replace thetray assembly onto the proximal tibia.

2.Replace any pins needed for stability andusing the appropriate sized fin punch, insertthe punch into the proximal tibial trial tray andimpact until fully seated (Figures 89 & 90).

Trialing

Figure 89

Figure 88

Figure 90

Resurfacing Patellar Preparation

33

The surgeon can choose from a free hand cutting technique with towel clips or if desired he or she can choose one of the followinginstrumented techniques.

Resection Guide Technique

1.Measure the overall thickness of the patella with the patellar calipers (Figure 91).

2.Subtract from this number the thickness of the GENESIS™ II round resurfacing patellarcomponent – 9mm.

Tip: The thickness of the GENESIS II ovalresurfacing patella varies by diameter.

3.The guide is set at the amount of bone thatneeds to remain after cutting the patella – i.e.the difference between the original patellarthickness and 9mm. The guide is set at this level by turning the knurled knob (Figure 92).

Figure 91

Figure 92

34

4.Cut the patella through the full dedicated sawguides (Figure 93).

5.Drill for the three pegs (Figure 94), insert theresurfacing patellar trial and remeasure. The overall thickness should be equivalent to theoriginal thickness (Figure 95).

Reaming Technique

The reaming technique described for thebiconvex patella on page 35 can be used withthe resurfacing patellar implant as well. Theonly differences in technique are to use thered resurfacing depth gauge, resurfacingreamers and the resurfacing drill guides.

Resurfacing Patellar Preparation

Figure 95Figure 94

Figure 93

Biconvex Patellar Preparation

35

Biconvex Patella

Instrument Assembly: Determine the appropriate diameter patellar implant and select the correctly sized patellar reamer collet and slide it into place on the patellar reamer guide (Figure 96).

1.Attach the patellar reamer guide to the patella.Tighten the patellar reamer guide on the patella(Figure 97).

2.Use the patellar calipers to measure thethickness of the patella (Figure 98).

Figure 97 Figure 98

Figure 96

36

Instrument Assembly:a. Attach the blue patellar depth gauge to the reamer

guide (Figure 99). b. Attach the matching sized patellar reamer dome and

patellar depth stop to the patellar reamer shaft (Figures 100 & 101). Lower the assembly through the patellar reamer guide until the reamer dome contacts the patella.

3.Swing the patellar depth gauge around so thatthe “claw” surrounds the patellar reamer shaft.

4.Lower the patellar depth stop by pushing thegold button until it contacts the patellar depthgauge. The patellar depth stop will automaticallylock in place (Figure 102).

5.Remove the depth gauge.

6.Ream the patella until the depth stop engagesthe patellar reamer guide.

Biconvex Patellar Preparation

Figure 102

Figure 100 Figure 101

Figure 99

Implant Assembly

37

1.Select the appropriate sized femoral/tibialcomponent(s) and the matching sizedfemoral/tibial wedges.

2.Using the tibial and femoral trials as a guide,assemble the femoral and/or tibial wedgeswith the 3.5mm hex screwdriver. Secure thewedges with the torque wrench by turninguntil a click is felt.

Tip: Screws are packaged sterile with theimplant wedge.

3.If a coupler is needed, select the appropriatesized coupler for the tibial or femoral component.To protect the coupler upon impaction, place theplastic LEGION™ stem/coupler impactor over thefemale end of the offset coupler implant. Insertthe male end of the coupler into the femoraland/or tibial implant taper. Impact the coupler atleast three times to ensure the taper lock isproperly engaged.

4. Select the appropriate length and diameter stemthat was used for the tibial and femoral trials.

5a.Cemented: To protect the stem tip uponimpaction, place the appropriate sized plasticLEGION stem impactor over the tip of thecemented stem. Insert the male end of the steminto the offset coupler or femoral and/or tibialtaper. Using a stable surface, impact the stem atleast three times to ensure the taper lock hasbeen properly engaged

5b.Press fit Stems: Insert the male end of the steminto the offset coupler or femoral and/or tibial taper.

Tip: For the press-fit slotted stems, ensure thatthe rotational mark on the stem lines up withthe rotational mark on the post of the femoraland/or tibial implant.

To protect the tip upon impaction, wrap orcover the tip of the press-fit stem. Using astable surface, impact the stem at least threetimes to ensure the taper lock has beenproperly engaged.

6.Attach the stem set screw, included in thestem packaging, by securing with a 2.5mmhex screwdriver on both sides of the femoraland/or tibial post.

38

1.Sublux the tibia anteriorly using a Hohmann orsimilar retractor. Place cement on the proximaltibia and seat the tibial implant with the tibialimpactor. Remove excess cement.

2.Flex the knee to 90º. Place cement onto the distal surface of the femur and insert the femoralimplant into position. Remove any excess cement.

3.Place the correct size tibial insert trial into thetibial baseplate and extend the leg to pressurizethe cement.

4.Assemble the patellar cement clamp to thepatellar reamer guide.

5.Apply bone cement to the patella.

6.Place the patellar implant onto the patella andclamp into the bone. Remove excess cement.

7. Remove the trial insert.

8.After all excess cement is removed and thejoint is clean, slide the tibial articular insertinto the tibial baseplate posteriorly, engagingthe locking mechanism.

9.Attach the articular inserter/extractor to the tibialtray. Lift the inserter superiorly until the anteriorlip of the articular insert is fully seated.

Implantation

Notes

39

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